1. Field of the Invention
The present invention relates generally to an outboard engine and, more particularly, to an outboard engine having an engine housing case construction which allows easy access to an engine for maintenance and inspection operations relative to the engine.
2. Description of the Related Art
Conventionally, a technique is known from, for example, Japanese Patent Laid-Open Publication No. HEI 8-99693 entitled "HOUSING CASE FOR ENGINE OF OUTBOARD ENGINE ASSEMBLY", which allows easy access to the engine for maintenance and inspection operations of the engine.
The conventional outboard engine assembly comprises a vertical multi-cylinder engine and a housing case for enclosing the engine. The multi-cylinder engine includes a cylinder block having a plurality of cylinders laid horizontally in vertical juxtaposition, a crankshaft extending vertically therethrough, and a camshaft located oppositely from the crankshaft and extending vertically. The engine also includes a cylinder head and a head cover faced rearwardly of the outboard engine assembly. The housing case includes an undercase for covering a lower part of the engine and an engine cover for covering an upper part of the engine. The undercase is provided with two work apertures at portions thereof which are axially aligned with bolts for securing the cylinder head to the cylinder block. These apertures are normally closed by rubber closure members.
For performing maintenance and inspection works on the engine, the engine cover and head cover are removed. Then, the closure members are removed for allowing insertion of a tool through the apertures so that the bolts can be untightened to thereby allow removal of the cylinder head.
In certain instances, it is desired that the head cover be attached to a top end of the cylinder head such that it extends along an axis of the camshaft. To meet this desire, it is necessary for the head cover to have a large depth dimension, thereby making the head cover large in overall size. When applied to the conventional engine, such a large head cover cannot be detached easily, because the undercase obstructs the detachment. To overcome this problem, one may propose to size up the undercase but this requires up-sizing of the outboard engine and hence is undesirable.